Tracker bar



March 1 1927.

1,619,690 N. G. BAKER TRACKER BAR Filed Jan. 22, 1925 Patented Mer. l, 1927.

UNUSED STATES lltl PATENT OFFICE.

NORMAN G. BAKER, 0F MUSCATINE, IOVIA.

TRACKER BAR.

Application lerl January rl`his invention is an improvement in tracker bars for automatic musical instruments, such as pianolas, band organs, and the like, and the principal object thereof is to n'ovide a tracker bar, made in two separable sections and having a removable dust screen interposed between the sections, with novel means for readily and quickly locking or unlocking the sections, in order that the dust screen may be readily removed for cleaning.

I will eXplain the invention with reference to the accompanying drawing which illustrates one practical embodiment thereof to enable others to adopt and use the same, and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings: l

Figure l is a perspective view of a tracker bar showing the two sections thereof locked together.

Figure 2 is an enlarged side elevation of the same, showing the two sections in unlocked posit-ion.

Figure 3 is a transverse section through the tracker bar. i

he tracker bar, as shown, is made in separable sections, a lower section l, upper or outer section 2. The vlower section l is adapted to be mounted in any desired manner upon the projecting portion A of the frame of the instrument, the outer surface thereof being llat and provided with one or more rows of perforations lb connected in the usual manner to the key, or note, suction tubes A of the instrument.

The outei section 2 of the? tracker bar, preferably made of brass, is likewise provided with one or more rows of perforations two and a 2b adapted to normally register with the pertorations lb in section l, when the sections are locked together, and the outer face of section 2 is preferably smooth and slightly rounded for the perforated paper music roll (not shown) making asliding Contact therewith in the usual manner.

Protruding from the outer face of section l at opposite ends thereof are two alignment pins 1c adapted to engage holes 2a in the under side of the outer section 2 when the two sections are super-imposed to insure that the two sect-ions, when locked together, will be properly aligned, with the pertorations 2b in section 2 registering with their respective perferations lb in section 1.

22, 1925. Serial No. 4,051.

A dust screen 3 of line mesh, and preferably of same area as the opposed faces of the tracker bar sections is interposed between the two sections l and 2, and also between two gaskets Sa and 3b, preferably of soft leather, mounted upon the adjacent faces of their respective sections l and 2. said gaskets having perforations therein registering with those in the sections l and 2 and also having perforations for the passage therepast of the alignment pins lC of section l, so that when the screen is interposed between the gaskets on sections l and 2, and the sections locked together, as hereinafter described, air will be prevented from entering the perforations around the screen 3 between the sections, while permitting air to enter the outer ends of perforations 2b in the tracker bar when the perforations in the paperl music roll register therewith, the air passing through the screen 3 before passing into the tubes A of the instrument.

The dust screen 3 must be removed for the purpose of cleaning, and for this purpose l have provided novel sliding cam plates for detachably connecting the sections l and 2 together. As shown, a plate 4 is slidably mounted on each side of the tracker bar, each plate 4 having elongated slots 4, therein adjacent their lower edges through which extend screws or headed pins 4b, projecting from the sides of section l, thereby permitting plates 4 to slide longitudinally of the tracker bar, handles or projections 4C being formed or provide-d on the plates to facilitate the movements thereof. but proventing transverse movement ot the plates with respect to t-he tracker bar. Extending downwardly from the upper edge of each plate 4 are plurality of parallel angularly disposed cam slots 4d, three being shown on each plate 4, adapted lto receive pins or studs 4e projecting from the sides of the outer section 2, whereby when the sections l and 2 are placed together, with alignment pins l" of section l entering the holes 2'LL in section 2, as the plates 4 are moved in one direction (toward the left in Fig. 2) the pins 4e will enter their respective slots 4d, and will be drawn downwardly by said slots, thereby locking the two section together and retaining the same in locked position, with the screen 3, and gaskets 3a and 3b, interposed therebetween; ibut when the plates 4 are moved on the opposite direction, the pins 4E will be forced upwardly, and will pass out of said slots 4d thereby unlocking the two sections l and 2 and hence permitting the removal of the screen from between the two sections. After cleaning the screen 3 the. same may be placed uponthe section l and section 2 super-imposed thereon with the pins lc of the lower section entering the holes 2a in sect-ion 2, and the two sections then locked together by means of vtl'ie cam plates 4, as above described.

My novel means for locking the two separable sections of the tracker bar together is simple and etlicient, and permits the sections being `readily unlocked in order to permit removal of the screen for the purpose of cleaning same.

I do not limit my invention to the exact form shown lin the drawing, for obviously minor changes may be made therein within the scope of the invention.

' I claim: y

l. A tracker bar coii'ipi'isingtwo separable sections, a screen between said sections, cam means Vfor detachably locking said sections together comprising a Vplate longitudinally slidably mounted on the side of one section and having vone or more angularly disposed cam slots therein extending inwardly from one edge and overlying the other section, and one or more pins on the other secton adapted to engage said slots.

2. A tracker bar comprising two separable sections; a dust screen interposed between said sections and a slidable cani llordetachably locking saidsections together, said means comprising a plate movably mounted 0n one section, and having a plurality of parallel angularly disposed cam slots extending inwardly 'from one edge adjacent the other section. and pins on the other secton adapted to engage said slots.

3. A tracker bar comprising a lined section; a removable section; a dust screen interposed between said sections; and slidable cam means for detachably locking said sections together, saidV means comprising plates longitudinally A movably mounted on the fixed section, and having plurality of parallel angularly disposed cam slots therein'extendingpinwardly from the edge, adjacent the removable sect-ion; and pins onthe removable section adapted to engage said slots. p

4. A tracker bar for musical instruments comprising a iiXed section adapted to be mounted on the said instrument; a removablel section adapted to be mounted on said fixed section; a dust screen removably interposed between said sections; means vfor aligningsaid sections; and slidable cam means for detachably locking said sections together, said means comprising plates longitudinally movablymounted on the fixed section, each plate having aV plurality of parallel singularly disposed cam slots therein l'extending inwardly from the edge adjacent the removable section; and pins on the removable section adapted to engage said slots. F a i 5. A tracker bar -or musical instruments comprising a fixed section adapted to be mounted on said instrument; areinovable outer section adapted to be mount-ed on said fixed section; aV dust screen'removably interposed between said sectons;` means for aligning said sections; gaskets interposed between said screen and sections; and slidable cam plates on each `side of said tracker bar for detachably locking said sections together, said cam plates having longitudinal slots therein adjacent the iiXed section; headed pins on said Xed section engaging said slots whereby said plates'will vbe longitudinally mounted 'on said `lifted section; said plates each having a 'plurality of parallel angularly disposed Vcam lslots extending inwardly from the edge adjacent said removable section; pins on. the removable section Vadapted to engage said cam slots; and handles on said plates "for moving same.v

ln testimony that l claim the foregoing as my own, l ailix my si gnature.

NORMAN BAKER. 

